Studies On Coloring Factors Of Yellow Fat Of Mongolian Cattle In Hulunbuir Grass Land

Being regional peculiar and superior meat resources, Hulunbuir Mongolian Cattle meat is characterized with delicious, cream flavored yellow fat, ranging from lemon to orange. However its color contributory factors, coloration procedure and mechanism of fat of the regional breed still remain uncertain. To make clear yellow fat coloring factors of the Hulunbuir grazing Mongolian Cattle, yellow fat samples of the peculiar breed, and white fat specimens of cattle, sheep and bactrian camel were also collected to conduct comparative study; b* value of yellowness, carotenoids, vitamin A (VA) and fatty acids (FAs) were detected, and finally, through correlation and comparative analysis, P-carotene was determined as the major yellow coloring factor, expelled Va and FAs.As the result, the b* values (X±SD,23.35±4.04) of yellow fat of Hulunbuir Mongolian cattle was significantly higher than that of cattle’s white fat. Applying saponification extraction process, thin layer chromatography and high performance liquid chromatography, the major yellow coloring factor was determined as β-carotene, no lycopene, lutein and other carotenoids were not detected;β-Carotene (1.60±0.54,x±SD) in yellow fat of Hulunbuir Mongolian cattle was significantly higher than that of white fat of cattle; no lycopene and lutein and other carotenoids were detected in cattle’s yellow and white fat, as well in sheep and camel; β-Carotene indicated significant positive linear correlation with b* value (Pearson correlation coefficient 0.540, P=0.007); whilst VA has positive correlation with β-carotene, however VA in yellow fat was significantly lower than white fat. Oleic acid, linoleic acid and linolenic acid indicated significantly positive correlation with b* value, however, oleic acid and linolenic acid showed no difference between yellow and white fat of cattle, while linoleic acid was significantly lower than white fat of cattle; the remaining FAs didn’t show correlation with β-carotene, thus FAs seemed no contribution to yellowness of the fat either.PCA profiling(samples projection in 3D space) by combined indexes, such as b* value, β-carotene, VA and FAs indicated that there are big gap/separation between livestock species and geographical origin(breed differences not dispelled), this means it is possible to build some robust meat species and origin discrimination or authentication model with these indexes and Chemometrics methodologies.Through the study, we can determine that yellow coloring factor of yellow fat of Hulunbuir Mongolian cattle is mainly β-carotene. Considering the yellow fat samples were collected in late autumn and winter time, the periodical contribution of other carotenoids, such as lutein, lycopene or other easily oxidized carotenoids still need further study.